The present invention relates generally to a torsion bar-type automotive vehicle suspension. More specifically, the invention relates to a torsion bar suspension which is compact enough to provide adequate road clearance for the vehicle.
In conventional torsion bar-type suspension, a lower suspension arm supporting a vehicle wheel via a knuckle is pivotably suspended by means of a torsion bar. The torsion bar is fixed to the vehicle body at one end by means of a bracket with a bushing assembly. In this case, the bracket must be large enough to accommodate the bushing assembly and allow the torsion bar to pass through the axial opening of the bushing assembly. Such brackets may provide only marginally sufficient road clearance for the vehicle. In other words, the bracket may be so big as to strike the road surface while the vehicle is travelling over rough roads.
In addition, since the bifurcated inner ends of the lower arm are connected to the torsion bar in axial alignment with respect to the latter, when forces are applied to the knuckle along the longitudinal axis of the torsion bar, such as during acceleration, deceleration and so forth, relatively large lateral forces are applied at the junction between the rear leg of the bifurcated lower arm and the torsion bar. Due to these lateral forces, the the bushing in the bushing assembly deforms laterally, resulting in compliance steering by which the toe angle of the wheel will change in the toe-out direction. As will be appreciated, due to this toe-out change, the cornering force will be reduced, thereby degrading driving stability.